Molecular Vision 2010; 16:1646-1653 <http://www.molvis.org/molvis/v16/a177> Received 9 June 2010 | Accepted 9 August 2010 | Published 16 August 2010
Š 2010 Molecular Vision
The effects of rapamycin on lens epithelial cell proliferation, migration, and matrix formation: An in vitro study Hongling Liu,1 Guangzhong Feng,1 Lan Wu,2 Shaoying Fu,1 Ping Liu,1 Wei Yang,3 Xiaomei Zhang1 (The first two authors contributed equally to the work) 1Department of Ophthalmology, The 1st Affiliated Hospital, Harbin Medical University, Harbin, P.R. China; 2Daqing Field Genaral
Hospithal, Daqing, Heilongjiang, P.R. China; 3Department of Cardiology, The 1st Affiliated Hospital, Harbin Medical University, Harbin, P.R. China Purpose: The objective of the present study was to investigate the efficacy of rapamycin on rabbit lens epithelial cell proliferation, migration, and secrcetion of extracellular matrix fibronectin (Fn). Methods: Rabbit lens epithelium cells (rLECs) were isolated from 1 month old rabbit. rLECs were either cultured for 24, 48, or 72 h with different doses of rapamycin (0.1, 1, and 10 ng/ml). The proliferation kinetics, proliferating cell nuclear antigen (PCNA) expression, and basic fibroblast growth factor (bFGF)-induced migration of rLEC was determined by methyl thiazol tetrazolium (MTT) assay, western blotting and transwell chamber assay, respectively. The effect of rapamycin on the synthesis of Fn was examined via immunofluorescence. Results: Rapamycin significantly inhibited rLEC proliferation and PCNA protein expression when administered doses and time periods except for 0.1 ng/ml for 24 h. bFGF-induced migration rLECs was inhibited by pretreatment with rapamycin for 48 h. Extracellular matrix Fn formation of rLECs was also reduced by rapamycin. Conclusions: In our study, rapamycin strongly inhibited rLEC proliferation, bFGF-induced migration, and extracellular matrix Fn formation. Thus, rapamycin may have a potential inhibition of posterior capsule opacificatin (PCO) and needs further study.
Posterior capsule opacification (PCO), known as aftercataract, is the main long-term complication of extracapsular cataract extraction (ECCE), with an estimated incidence of 20%â&#x20AC;&#x201C;40% of cases within 5 years after surgery [1]. The cellular mechanisms responsible for PCO are still unclear. Previous studies have suggested that the proliferation, migration, and epithelial-mesenchymal transition (EMT) of the remaining lens epithelial cells (LECs) after cataract surgery are a major cause of PCO [2]. The response of LECs can be considered a wound-healing reaction resulting from the activation of inflammatory cells and production of cytokines and growth factors after surgery, influenced by the extracellular matrix (ECM) of the lens capsule [3,4]. The inhibition of LECs proliferation, migration and secreting extracellular matrix would be an ideal way to prevent this complication. Rapamycin is one kind of potent immunosuppressant and antiproliferative drug. Rapamycineluting coronary stent has been safely and clinically used, which remarkably reduced the rates of restenosis and associated clinical events after percutaneous coronary revascularization. The mechanisms may be by inhibiting Correspondence to: Wei Yang, Department of Cardiology, The 1st Affiliated Hospital, Harbin Medical University, 23 Youzheng Street, NanGang District, Harbin, 150001, P.R. China, Phone: 86-451-85553950; FAX: 86-451-85553922; email: hydliuhl@tom.com
proliferation and migration of smooth muscle cells (SMCs) [5-7]. In our previous study, RAPA was loaded into the polylactide-glycoli acid (PLGA) layer on the surface of intraocular lens (IOLs) which prevented formation and development of PCO in rabbit model for 24 weeks [8]. The topical application of immunosuppressive drug with antiinflammatory and antiproliferative effects seems to be promising. However, there is still a lack of information about the biologic effects of rapamycin on lens epithelium cells. Thus, the aim of this study was to evaluate the effects of rapamycin on the three major processes of PCO (proliferation, migration, and matrix synthesis capability) of rabbit lens epithelium cells (rLECs) in vitro. METHODS Cell culture and treatments: All procedures were conducted in accordance with institutional guidelines for the use of animals in scientific research and adhered to the ARVO Statement for Use of Animals in Ophthalmic and Vision Research. rLECs were isolated from the lenses of White New Zealand Rabbits at 1 month of age. The whole eyes were rinsed in 96% ethanol for 30 s to minimize a possible bacterial contamination of the lenses from the eye surface during lens preparation and followed by washed in phosphate bufferedsaline solution (PBS). The cornea was dissected aseptically
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